3-EPA
United States
Environmental Protection
Agency
EPA832-B-01-004
September 2001
Office of Water Washington, DC
Overview To
Watershed Assessment:
Tools For Local Stakeholders
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EPA832-B-01-004
September 2001
Overview To Watershed Assessment:
Tools For Local Stakeholders
Printed by:
Office of Wastewater Management
U.S. Environmental Protection Agency
Washington, D.C. 20460
Internet Address (URL) • http://www.epa.gov
Recycled/Recyclable • & Printed with Vegetable Oil Based Inks
on Recycled Paper (Minimum 50% Postconsumer)
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Table of Contents
Preface i
Foreword ii
Introduction 1
Watershed Framework
Definition Of Assessment
Coordinating Data
Purpose Of The Assessment
The Watershed Parntership
Purpose Of The Guide
Roles And Responsibilities 5
Federal Government Agencies
States/Tribes
Local Governments
Permitted Dischargers
Drinking Water Utilities
Other Interested Parties
Developing A Watershed Assessment Plan 11
Establish Assessment Goals And Objectives
Establish Baseline And Conduct Preliminary Assessment
Electronic Data and Geographic Information System
Data Analysis
Identify Data Management and Analysis Procedures
Identify Process For Periodic Evaluation
Tables
Table 1 Potential Roles And Responsibilities For
Watershed Assessments 10
Table 2 Summary Of Data Typically Utilized For
Watershed Assessments 21
Appendices
Appendix A Generic Scope For Watershed Assessment
Appendix B Reports And Documents
Appendix C Electronic Resources
Appendix D Mapping And CIS Resources
Appendix E Training Opportunities
Appendix F Important Contacts
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Introduction
The Watershed Framework
The Watershed Management Framework is being used increasingly to improve
the receiving water quality of the nation's rivers and streams and the uses of its
waterways. Using the watershed unit, rather than governmental boundaries as
has been the case, provides for comprehensive, sensible water resource decisions
and strategies, and addresses more effectively the full range of stakeholder
concerns.
The "watershed approach" has long
originated at the local watershed level,
because of its practicality in problem
solving among people, jurisdictions,
and industries sharing a water resource.
Now this approach is receiving a great
deal of focus in the United States
associated with the United States
Environmental Protection Agency's
(EPA) more formal development of the
watershed approach. With rivers
frequently serving as jurisdictional
boundaries, water management concerns are best handled at the watershed, rather
than jurisdictional, level. Working at the watershed level appropriately involves
those most knowledgeable about the specifics of the river and its watershed: the
interested governments, industries, citizens, and a full range of other interested
stakeholders.
Various catalysts might lend impetus to the formation of a watershed
organization: a single or compound water pollution issue, accelerated growth, or
the proposal of a large industry or other project. The partnership formed by the
watershed organization provides for one of the most critical elements to address
water management: coordination of data from varying sources on a different
geographic basis—the watershed.
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Overview To Watershed Assessment
The watershed approach fosters the coordinated implementation of programs to
control point source discharges, reduce polluted runoff, and protect drinking
water sources and other sensitive natural resources such as wetlands. A watershed
approach also highlights cost-effective opportunities to go beyond reducing
chemical pollutant concentration, and instead to think about ways to enhance the
overall health of the aquatic ecosystem and preserve biodiversity. The watershed
approach also fosters greater interest from the public and provides a foundation
for partnerships among federal, state, tribal, and local public and private
watershed stakeholders.
Definition Of Assessment
The assessment phase is one of the first elements of effective water resources
management. This document provides a set of "tools" to support these
watershed-level frameworks to conduct the assessment phase. Assessment refers to
a focused or comprehensive overview of key conditions and trends representing a
baseline status. The assessment generates recommendations for management
alternatives, a comprehensive plan, and a means of implementation.
In the case of water quality, it is essential for the assessment to include all available
monitoring data. However, while the term 'assessment' can mean water quality
monitoring, an environmental assessment report for a watershed should include
all related material, especially land uses, soils and topography. The assessment
should coordinate all relevant datasets and maps, which must be analyzed,
organized and displayed so as to be most useful to later interpretation and
management.
This effort requires intimate knowledge of the environmental conditions in the
watershed, and will rely on the mix of agencies and institutions that must play a
part in achieving coordinated and comprehensive solutions to today's complex
pollution problems. Federal agencies can provide technical and, in some cases,
financial assistance to facilitate watershed management. State and tribal leadership
can bring all levels of government, the private sector and the public together to
make the watershed approach work. But a watershed-up level approach reflects
those most interested and affected in the watershed, who are best able to identify
relevant data and interpret it in the context of the specific watershed.
Watershed assessment focuses on the overall watershed management program. It
is critical in identifying pollutants of concern and the relative role of point and
nonpoint pollutant sources, strategizing pollution prevention and control
measures, and tracking progress and making adjustments towards meeting
watershed goals and objectives.
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3
Introduction
Coordinating Data
Federal water quality monitoring and assessments are important aspects of many
EPA programs authorized under the Clean Water Act, including the National
Pollution Discharge Elimination System (NPDES), §106 State/Tribal Water
Quality Program Management grants, § 305(b) Water Quality Inventory reports,
and §300j-13 Source Water Protection under the Safe Drinking Water Act. The
United States Geological Survey (USGS) also conducts instream chemical
monitoring through its National Ambient Water Quality Assessment (NAWQA).
However, due to the different program objectives, results from these programs are
typically difficult to compare. Watershed-based assessment provides an excellent
opportunity for coordinating information from existing and new federal
programs.
At the state and local levels, information about pollution sources and impacts in a
receiving water is collected and maintained by different organizations and
agencies with little or no communication among them. For example, point source
monitoring data may be maintained by the permit compliance branch of a state
regulatory agency, biological monitoring data may be maintained by the fisheries
division of the same state regulatory agency, and storm water outfall monitoring
data may be gathered by the municipality. Sharing of collected, watershed-
specific data among local and regional decision makers maximizes its usefulness
and allows targeting of limited local dollars to collect any monitoring data
necessary to fill in the gaps.
Watershed assessments do not necessarily require extensive additional resources if
existing efforts are expanded to include a data coordination role. A useful
watershed assessment report can be generated through better organization of
existing information, supplemented with changes in existing monitoring
procedures where necessary. The preliminary data review will identify if any
additional water quality sampling, monitoring, and assessment is necessary to
develop management strategies.
Purpose Of The Assessment
A watershed-based assessment provides a comprehensive evaluation of conditions
and trends in the entire watershed. Watershed-based analysis can then be used to
address the following objectives:
1. Characterize conditions and trends in water quality and watershed health;
2. Determine causes of existing and future water quality and watershed health
problems;
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4
Overview To Watershed Assessment
3. Aid in the development, prioritization, and implementation of an overall
watershed management program to prevent or correct the identified
problems;
4. Establish a baseline and assess progress of overall watershed management
activities or effectiveness of pollution prevention and control practices;
5. Support documentation of compliance with permit conditions and/or water
quality standards and criteria;
6. Increase ecological and stakeholder benefits with minimal additional effort;
7. Provide data to calibrate and verify watershed/water body models;
8. Educate and inform the public; and
9. Refine the existing monitoring program.
The Watershed Partnership
Watershed partnerships should include all affected governments, and can be most
effective through inclusion of representatives of municipal utilities, industries,
business groups (such as the local Chamber of Commerce) and conservation
advocacy organizations. Through such partnerships, resources are shared, roles are
clarified, and cost effective practical solutions are put in place. As a result, a better
informed and more involved constituency can make a commitment to lasting
environmental improvements in their own community. While the goals,
resources, and characteristics of the partnership will vary from watershed to
watershed, this document outlines the typical roles and responsibilities of key
watershed stakeholders and the strengths each brings to the partnership.
Purpose Of The Guide
This document describes the key steps to develop and implement watershed
assessment plans. The term watershed assessment used here includes a variety of
data collection, mapping and water sampling methods to characterize the
environmental health of a watershed (see Table 1, page 10, for examples).
This document provides essential tools for local watershed stakeholders in overall
assessment principles and structure. The second half is the Resources section,
which contains essential reference material that will support the organization in
proven techniques, so as to get a rapid start on devising the plan. The References
section includes Web sites and electronic mapping (GIS) file availability, as well as
extensive sources for paper map products fundamental to understanding a
watershed. The Web-based version of this document is an electronic "portal" to
all types of necessary material for an individual watershed assessment.
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Roles and Responsibilities
Watershed assessment is inherently intergovernmental and interjurisdictional,
because watershed boundaries do not correspond to political boundaries.
Initiating a watershed assessment presumes a watershed coordinating group (or
task force, commission, etc.) reflecting the appropriate balance of stakeholder
concerns in the watershed. A coordinated assessment effort should encourage all
stakeholders to become involved in the planning and implementation process,
with the representatives of the stakeholders joining to form a watershed-based
assessment team. Ensuring the appropriate participation of these various
stakeholders at the outset will make efficient use of resources and avoid later
obstacles.
The coordinator or coordinating group will serve as a central information
repository, a QA/QC coordinator, and a general organizational contact. The
group will establish goals and objectives, provide access to necessary data, and
manage the scope and coordination of analysis. Stakeholders can provide data,
scientific expertise, manpower, and even financial backing for assessment efforts.
See Table 1 for a suggested responsibilities matrix.
Specifically, the coordinating group should have the ability and resources to
perform the following tasks:
• Establish the Watershed Assessment Plan goals and objectives;
• Provide existing data and access to information that will aid in implementing
the assessment strategy;
• Provide technical oversight and scientific expertise reflecting their
responsibilities;
Maintain appropriate contact with elected officials and appointed boards;
and
• Develop funding options.
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Overview To Watershed Assessment
Federal Government Agencies
U.S. EPA can provide assistance through guidance, training, technology transfer,
database assistance (e.g., STORET, BASINS, etc.) and by providing information
from special projects in
the watershed such as
TMDL development.
Surf Your Watershed
A ierv«e to H*lp You Locate, Uie. and Mure
l liifirtiiidtloii dbwjt four F\AUC
Access to extensive
information can be
accessed via EPA's "Surf
Your Watershed"
program. EPA
developed this Internet
capability to facilitate information sharing by watershed, county, or other
geographic unit. "Surf Your Watershed" (at URL http://www.epa.gov/surf)
allows users to access information on a watershed level, including data such as
ambient water conditions, water column chemistry, biological integrity, bottom
sediment characteristics, instream designated uses or impairments or special
protection areas, instream flow data, point source discharge data (e.g., compliance
monitoring data), and watershed land use data. The site's Index of Watershed
Indicators compiles information on the condition and vulnerability of watersheds
in the United States. Fifteen indicators, including assessed waters which meet
designated uses, fish consumption advisories, and contaminated sediments, are
combined into an overall index score for every watershed in the nation. The
Index also allows users to learn more about other organizations in their watershed.
Watershed managers at the state and local level may access EPA's STORET
(STOrage and RETrieval) data system (at URL http://www.epa.gov/owow/
STORET). Available in PC or LAN version, STORET is a national system that
can store virtually all types of water quality and biological data, and allows for data
sharing among organizations. To aid in data sharing, a specific set of quality
control measures is required for any data entered into the system.
Another important database available from EPA's Office of Water is the Better
Assessment Science Integrating Point and Nonpoint Sources (BASINS)
geographic information system (GIS) application. BASINS includes some of the
data and modeling tools required for planning level evaluation and modeling of
watersheds. This system assists federal and state agencies in performing large-scale
assessments of watersheds, identifying and prioritizing pollution sources and
issues, evaluating impacts on water quality, developing total maximum daily loads
(TMDLs), and predicting the effects of management scenarios. BASINS'
databases and tools are directly integrated within an Arc View GIS environment.
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Roles and Responsibilities
(Users should be alert to the importance of checking for updates via BASIN's
Web site to obtain current data.)
In the case of an interstate watershed assessment, a federal agency such as an EPA
Regional Office can assist in facilitating proposal development among
stakeholders. Finally, where the State/Tribe is not the permitting authority, U.S.
EPA is responsible for approving all proposals affecting regulatory requirements.
States/Tribes
Due to the State's role in setting water quality standards and permit limitations, it
is important that the State be involved to the greatest extent possible. The State
can act as a lead coordinator, a partner, or as a technical resource to the local
watershed group. (Some Native American Tribes hold certain environmental
regulatory powers parallel to those of the State on Tribal lands, under PL638, and
must be included in any watershed organization linked with those lands.)
North Carolina is a good example of the State acting as a lead coordinator. North
Carolina has developed a plan where the State conducts comprehensive monitoring
of waterways in all major
watersheds on a five-year rotating
basis. Where programs such as
this exist, local watershed
monitoring organizations can
provide valuable assistance in
expanding the State program.
This is achieved by increasing the
number of monitoring sites, or
expanding the number of
parameters to be monitored.
Where local organizations
participate in established State
programs, these organizations
should work closely with the
State to ensure the new programs
support the overall State effort.
In contrast, North Dakota and
Nevada are examples of limited
Statewide watershed assessment
programs coordinated and
implemented locally. While
EPA and the State/Tribe are
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8
Overview To Watershed Assessment
available to provide technical guidance, the assessment programs are tailored to
meet local resources, designated use goals, and local watershed management plans,
if they exist. Another advantage of a locally driven assessment program is that
those actually residing in or around the watershed are actively involved and
therefore, more likely to support the assessment results. Finally, by maintaining a
locally driven assessment plan, the assessment goals can better be linked to the
overall goals of the local watershed management plan. Even with the organization
and actual assessment being conducted by the local watershed team, it is
important that EPA or the State/Tribe continue to provide guidance on
assessment techniques and program design to ensure compatibility with federal
and State water protection programs.
Finally, there are programs where both the State and local watershed organizations
have played leading or supporting roles in leading the assessment effort. The
State of Maryland, for example, has acted as lead agency in protecting major
waterways, such as the Chesapeake Bay and major tributaries. The regional
organization the Metropolitan Washington Council of Governments, has served
to provide technical assistance and to coordinate intergovernmental activities in
the Anacostia Watershed, with key involvement of the federal government
because of the extensive federal lands. The conservation-oriented Audubon
Naturalist Society, and area county governments have been the catalysts in
volunteer monitoring of the headwaters of local streams and of the Anacostia
River.
Local Governments
Local governments are critical to the assessment of watershed conditions because
of their unique land use authority, and their understanding of pollutants of
concern, local impacts, and historical and projected land use changes. Their land
use authority is key in providing information on environmental requirements in
the process of land development, and in developing potential strategies, like
requiring storm water quality BMPs for new development. They are sources of
information on environmental problem areas, BMP locations, community
interests, and local initiatives. In addition, local governments may play a major
role in monitoring subwatersheds and areas that go beyond those covered by the
State. Local governments are good sources for current and future land use
information. Many localities have GIS databases including forecasts for housing
and employment, which forecasts will be much more accurate than assuming full
build-out according to zoning and the comprehensive plan.
Watershed-based initiatives are often initiated by local governments, frequently to
protect a drinking water supply. For example, in Northern Virginia, local
governments with lands draining to the Occoquan Reservoir formed a Policy
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9
Roles and Responsibilities
Board to serve as a forum for discussion of changes and strategies within the basin.
The Occoquan Basin Policy Board funds a technical assistance committee to
examine nonpoint source control strategies (staffed by the Northern Virginia
Planning District Commission) and retains an independent university-based
monitoring lab. Significantly, the Policy Board includes not only the local
governments and their water and wastewater utilities, but the Soil and Water
Conservation Districts and citizen appointees.
Permitted Dischargers
Dischargers will have experience in point source and ambient water quality
sampling techniques, as well as quality assurance and quality control procedures.
Dischargers can also be a valuable resource in assessing existing ecosystem
conditions because they are likely to be familiar with local habitat and water use.
Finally, permitted dischargers can provide financial resources for instream
monitoring (water column, aquatic biota, etc.) If approved by the regulating
authority, an offset may be provided of limited reductions in currently required
effluent monitoring, as guided by EPA Burden Reduction Guidance.
Drinking Water Utilities
Utilities and agencies charged with providing and monitoring drinking water
have a strong interest and scientific expertise in watershed monitoring and
management. Source water monitoring is essential to the "multi-barrier" approach
to treatment of surface water. The multi-barrier approach uses source water
protection as one of three techniques to assure drinking water quality. Utilities
monitor drinking water intakes and often monitor at upstream stations. These
assessment resources could be joined with others in the watershed for a more
comprehensive picture of the contaminants of most concern for both drinking
water and primary contact (swimming).
Other Interested Parties
Other stakeholders may represent key affected industries, environmental advocacy
groups, and expert resources. In forming the watershed organization, the
following constituencies should be identified and considered for inclusion:
• Environmental groups;
• Agricultural organizations such as the Soil Water Conservation districts or
Farmers Cooperatives;
• Local businesses and business groups such as the Chamber of Commerce;
• Universities and research scientists; and
• Civic groups and concerned citizens.
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Overview To Watershed Assessment
Such stakeholders can contribute to the success of a watershed-based assessment
program through their expertise, knowledge of local conditions, and involvement
in the watershed. Volunteer monitoring programs can provide high quality data
that is valuable in conducting a watershed assessment (See References entries on
Volunteer Monitoring). Volunteers can receive technical training for monitoring,
which covers sampling techniques and reliable quality assurance/quality control
(QA/QC) measures.
Table 1. Potential Roles and Responsibilities
for Watershed Assessments
Task
Office
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Local
Regional
State
Federal
Permitted Dischargers
Drinking Water Utilities
Citizens
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Developing A Watershed Assessment Plan
There is no single, correct method for developing a watershed assessment plan.
The process will be different for each watershed due to differences in critical
challenges, natural resources, watershed conditions and trends, and relative
impacts of various pollutant sources, all of which drive watershed goals and
objectives. A generic Watershed Assessment outline is provided in Appendix A,
but each assessment plan must be designed specifically for each watershed.
The process for developing a watershed assessment plan is outlined below. More
information on each element of the process is presented below.
Establish Assessment Goals And Objectives
v Establish assessment goals and objectives
v Establish a baseline
Jtlduct 3 pr^li
j „*%. .
s Conduct a preliminary assessment
>•'" Select data collection methods
-•'' Identify data management & analysis
procedures
-•" Identify process lor periodic assessment
- -Jfr
Before developing a watershed assessment plan, watershed stakeholders should
agree on the purpose of the assessment effort, as guided by the established goals of
the overall watershed program. Setting watershed assessment goals and objectives
helps stakeholders understand the benefits and limitations of watershed
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Overview To Watershed Assessment
assessment activities. Implementing a multi-focused assessment will help achieve a
successful and dynamic program.
In particular, watershed stakeholders should address the following questions in
setting watershed assessment goals and objectives:
• Where are the known environmental problem areas and pollutants of concern?
• What are the major sources of impairment? Or is this a relatively unimpaired
basin?
• What data/information is needed? By whom?
• What sources of information exist? What are the apparent gaps?
• What intensity of additional field monitoring, if any (water quality, biota, etc.)
is required to meet the goals of a watershed management/protection plan?
• How will the assessment and management program be sustained over time?
What will be the availability of future resources?
• Who is responsible for what? What regulatory authorities affect the plan and
its findings?
The goals and objectives of any watershed assessment plan must be clearly
defined. Yet the needs for assessment data will change over time as human
activity, pollution controls, or watershed management activities are implemented.
Periodic review of the watershed assessment plan goals, objectives and protocols
will ensure that the data collected is timely and relevant.
The generic scope for a Watershed Assessment at Appendix A can be focused
toward potential impacts of anticipated activities, as well as on pristine areas to be
protected. A comprehensive document will include a complete geographic grid.
Establish Baseline And Conduct Preliminary Assessment
Definition Of A Baseline
The next step in the development of an assessment plan is to establish a baseline
of conditions within the watershed. A baseline is a "snapshot" of environmental
and other relevant conditions at a point in time which will serve as a point of
reference for management strategy priorities, and for future changes in the
watershed. Watershed data collected prior to the implementation of proposed
pollution controls and other management activities can be used to establish a
baseline for determining the success of the overall watershed management plan,
and to adjust the plan as time passes.
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Developing A Watershed Assessment Plan
;Trencl ami Load Stations In Lower Vlrglula Watersheds
^ rs ^"-'^i-'a.''- • ri r>Sv -ie ff& j- \
^^L^T^:
Coordination By Watershed Boundaries
Data coordination is one of the most useful tasks of the entire watershed
assessment. Extensive regulatory requirements and local concerns demand that an
enormous amount of data is collected under various programs—but rarely is this
data organized by watershed. Indeed, the challenge of carving out datasets
relevant to the watershed, and coordinating the data in comparable terms, may be
one of the biggest efforts undertaken by the watershed organization, but the
results will provide an unprecedented view of the watershed.
The organization and availability of data and maps can depend on the boundaries
that delineate a community's watershed. Watersheds are organized by hydrologic
units which are classified into four levels: regions, sub-regions, accounting units,
and cataloging units. Each hydrologic unit is identified by a unique hydrologic
unit code (HUC) consisting of two to eight digits based on the four levels of
classification in the hydrologic unit system. Hydrologic units and codes for
specific communities can be accessed electronically or through government
agencies.
It is important to recognize that assessment activities include a broad range of
existing data and information. Table 2 at the end of this section provides a
summary of types of data that may be useful in watershed assessments. To reduce
costs, watershed stakeholders should maximize the use of these existing resources
and minimize duplication of monitoring and data collection efforts.
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Overview To Watershed Assessment
Many agencies are also good sources of historical information and data trends.
Baseline analysis should include data records over a period of years, to assess areas
of improvement or decline and trends in pollution sources (e.g., conversion of
forested land to urban).
Readily accessible sources include a combination of federal, state and local data
sources, such as:
• Existing assessments of water bodies (§ 305 (b) reports)
• Impaired waters (§303 (d) list)
• NPDES permit monitoring data
• Safe drinking water permits
• USGS topographic, hydrological and water quality sampling data
• Land use (existing actual land use via aerial photos; zoning and comprehensive
plans; and land cover related to resource industries such as forestry and
agriculture)
• Population and employment growth trends
• Soils (especially erodibility index) and subsurface geology
• Biological resources; rare, threatened, and endangered species
In addition, agencies such as the U.S. Army Corps of Engineers, the U.S. Fish
and Wildlife Service, the U.S. Census, and state departments offish and game
maintain important background information (e.g., population growth, wetlands
status, general land use trends). Statistical documents are also maintained in
county, state and federal court houses. Local colleges and universities with
departments pertaining to the physical environment often have abundant
resources. Academic credentials of university staff can assist the watershed
organization, and can be a low-cost research aid if the research goals of the
watershed organization are reconciled with those of the academic institution. In
addition, assessment data collected from similar watersheds should also be
considered. For example, data associated with the Nationwide Urban Runoff
Program (NURP) of the 1980's may be useful in predicting storm water
pollutant loads from specific land uses. Likewise, accepted performance
efficiency data for pollution controls from credible sources may substitute for
duplicative monitoring of individual pollution controls.
Stakeholders should, therefore, invest significant time in the identification of
existing sources of data before any additional monitoring is undertaken. A
thorough effort at this stage can help identify data gaps and prevent duplication
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Developing A Watershed Assessment Plan
of efforts and may also result in
the identification of additional
stakeholders.
Other useful resources (see
Appendix D) are large-scale aerial
photos, remote sensing data,
satellite images, and historical
photos. A rectified electronic base
map with locational (preferably
latitude/longitude) information is
essential for proper integration of
data by watershed, as well as for
spatial analysis systems such as
CIS.
Electronic Data And
Geographic Information
Systems (GIS)
The advent of the Internet and
more powerful desktop
computers offers an
unprecedented resource for the
watershed organization. Much of
the data outlined above may be available electronically, and most government
agencies maintain World Wide Web sites to provide easy access and assurance of
current data. Ease of use, and widespread availability of computers with access
to the Internet, means that electronic access is a tool within the reach of even the
smallest watershed organization, in technical difficulty and affordability.
The use of GIS mapping resources, such as the USGS at the federal level, as well
as state and regional GIS agencies, does not presume that the watershed
organization possesses GIS software or trained personnel. Many of these
mapping resources provide paper maps, and can sometimes produce specific
combinations of data "layers" custom printed (and provided electronically) by
some agencies. Most importantly, the advent of GIS has meant faster, cheaper,
and more informative map creation—with provision for spatial analysis—by the
agencies responsible for mapping. But the GIS tool is most appropriately used
when spatial data is both analyzed and displayed electronically, for coordination
and conversion of data by watershed.
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Overview To Watershed Assessment
Data Analysis
Once the baseline data set has been organized, the next step is to examine,
analyze, and evaluate the data to determine watershed conditions. Stakeholders
should use existing data to identify: areas not meeting water quality standards,
areas showing other signs of impairment, significant water resources for
protection, and likely or potential sources of impairment. The combination and
organization of data should aid stakeholders in screening for priority areas for
additional watershed assessment activities, and for targeting pollution control
implementation.
Methods For Additional Field Data Collection
The analysis of the baseline dataset may determine that additional data and
information is needed to better characterize watershed conditions and to meet the
goals and objectives of the watershed assessment plan. With the objectives of the
assessment plan clearly understood, specific details such as what parameters to
monitor, monitoring station locations, and monitoring frequency can be
developed (see References). In particular, data on biota is not typically collected
on a systematic basis under the various Clean Water Act requirements, but rather
by the U.S. Fish and Wildlife Service, and by State fisheries agencies. Similarly,
most Clean Water Act requirements place an emphasis on ambient, or dry
weather, water quality. Communities subject to the storm water rule (Municipal
Separate Storm Sewer, or MS4) may already be conducting some wet weather
monitoring.
The watershed organization can play a key role if it is determined that the desired
additional monitoring data can be supported at the appropriate technical level.
Assistance that can be provided by the coordinating body members includes:
• Identify data inadequacies
• Develop assessment strategies, such as coordinating volunteer monitoring
programs with appropriate Quality AssuranceXQuality Control (QA/QC)
• Collect comparable data, conduct sampling, analyze samples, and assess habitat
conditions
• Interpret and evaluate monitoring results
• When appropriate, advise the permitting authority on possible substitutions of
ambient monitoring for effluent discharge monitoring (in accordance with EPA
Burden Reduction Guidance)
A field data collection plan must be prepared and possibly approved by reviewing
authorities (see Appendices B and C). As in the original data collection effort, the
types of field data collection, monitoring and sampling activities to be included in
a watershed assessment should be determined using the assessment goals and
objectives identified earlier in the process.
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Developing A Watershed Assessment Plan
Water quality or biota field data collection methods must address how, where,
when, and by whom samples should be taken (and who will pay the costs). EPA
has established protocols for Quality AssuranceXQuality Control (QA\QC) for all
sampling and analysis. The data collection plan should also address safety
measures.
For example, to accurately document the impact of wet weather flows,
monitoring and sampling strategies must reflect the unique characteristics of wet
weather flows, including the altered flow regimes and storm event pollutant
loadings which vary with watershed land cover conditions. Therefore, the
baseline assessment should be designed to provide the necessary information
about land cover and point sources to assess the relative contributions of pollutant
sources. General information on water quality impairment can be used to
determine the right mix of monitoring, in consultation with the state offices
responsible for this monitoring. Table 2 at the end of this section provides a
summary of the different types of
monitoring.
Selecting the appropriate
parameters to sample is one of the
core decisions in developing a
watershed monitoring plan. The
plan should include a range of
physical, biological, and chemical
parameters to ensure that
sampling will provide an accurate
picture of the ecosystem. The
goals and objectives of the
assessment plan (e.g., baseline
characterization, problem
identification, monitoring
compliance) will help determine
parameters to use.
Recognizing that monitoring
needs to encompass wet weather
impacts allows for a wide variety
of sampling parameters from
which to choose. The
parameters can be grouped as
physical (e.g., flow hydrology, precipitation, channel morphology, turbidity),
water quality (e.g., dissolved oxygen, BOD/COD, suspended solids, temperature,
pH, conductivity, nutrients), health of the aquatic community (e.g., fish, macro
invertebrates, aquatic habitats, sediment deposits), health of the terrestrial
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Overview To Watershed Assessment
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community (e.g., waterfowl, reptiles, stream bank erosion, riparian habitat),
aesthetics (e.g., trash, floatables, oil), human health (e.g., toxics, bacteria, metals),
and indirect parameters (e.g., beach closures, fish advisories). Successful
monitoring programs will combine biological and physical as well as chemical
parameters to measure impacts of pollution, locate pollution sources, and track
changes over time.
Generally, monitoring sites are selected using one of two approaches: probabilistic
or tiered. Probabilistic approaches use a limited number of random samples to
estimate trends within a larger
geographic area. The use of
random samples minimizes bias in
sampling site location, and
therefore, a greater representation is
achieved. In watersheds where
little is known about environmental
conditions, probabilistic
monitoring may be a good place to
start. Several States are using this
approach to broaden their
knowledge of watersheds. For
watersheds where more
information exists about
conditions, a tiered approach may
be more useful in creating a base
program to track long- term trends,
target monitoring in specific
regions for management purposes,
and establish a random or spot
check to identify unrecognized
problem areas.
Sampling frequency will vary from watershed to watershed depending on the
goals and objectives of the monitoring plan. When considering frequency, it is
important to consider that sampling should be conducted during both dry and
wet weather for a true watershed assessment. For wet weather monitoring, the
number of sampling events per year should be sufficient to address seasonal
variability, and must also provide an adequate number of observations for
statistical analysis of the wet weather water quality impacts. The watershed
assessment plan should also establish a minimum targeted rainfall event as well as
a minimum antecedent dry period between rainfall events. In addition, the
watershed monitoring plan must address implementation issues such as record
keeping and reporting, scheduling, financial resources, and ongoing staff
responsibility.
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Developing A Watershed Assessment Plan
Quality assurance/quality control (QA/QC) procedures are essential to any
watershed monitoring plan. They help assure data accuracy, continuity, and
defensibility. Traditional QA/QC procedures such as documenting sample times,
locations, and clarifying confounding factors are essential to ensure accurate data.
Testing and certifying samplers for each type of sampling (e.g., different levels of
certification ranging from debris identification to measuring vegetative overhang
to subspecies macroinvertebrate identification), can help ensure the data is
accurate. Standard operating procedures also ensure that the appropriate
parameters are measured by approved methods.
Identify Data Management And Analysis Procedures
The watershed assessment plan should address data management including type
of data base, methods for data analysis, quality assurance and quality control
methods, modeling strategy (if appropriate), and how the data will be used to
support the overall goals and objectives.
When developing a comprehensive watershed assessment plan, it is important
that collected data be useful beyond the network of sampling stations. By
ensuring compatible collection methods, comparable detection limits, uniform
analytical methods, and common/compatible storage software, will increase the
value of collected data for planning purposes, to enable comparisons to other
watersheds, and also potentially for compliance purposes. Due to the statistical
complexities of comparing different data, the statistical level of confidence at
which the program objectives are achieved should be defined during the
development of the monitoring program. While these issues will likely be
encountered when acquiring information from outside agencies, using compatible
monitoring protocols within the watershed can avoid these pitfalls as the
watershed assessment progress.
Identify Process For Periodic Evaluation
Periodic review of the watershed assessment plan is essential to evaluate whether
the plan is meeting its intended goals and objectives, and to effectively target
monitoring resources. It also helps evaluate whether Best Management Practices
or other wet weather controls are helping to meet the goals and objectives of the
watershed management plan, such as improved water quality, species diversity, or
wildlife habitat. Data needs may change over time, and periodic review can help
identify targets for revising monitoring frequencies or locations.
In addition to reviewing watershed assessment data, periodic review includes
review of monitoring and sampling protocols. Periodic review can help determine
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20
Overview To Watershed Assessment
which monitoring sites need continued base monitoring, which are targets for
spot monitoring, and which should be targeted monitoring locations. Each
monitoring point should be reviewed to determine whether parameters, sampling
frequency, location and analytical procedures continue lead to data that meets the
proposed goals objectives. Reviews should focus on measurable quantities, such as
number of samples planned/analyzed, data confidence scores, or water quality in
areas where BMPs have been implemented. As the watershed assessment
progresses, monitoring sites may be covered by each of these monitoring methods,
new locations can be determined, and results of the assessment can evaluated. If
any component of the assessment does not meet overall goals and objectives, the
component should be revised, and reviewed again.
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Table 2. Summary of Data Typically Utilized for Watershed Assessments
Data Type
Base low
Water quality
Storm low
Water quality
Aquatic biota
Physical habitat
Sediment
Ground water low
Description
water quality sampling during non-storm
conditions
water quality sampling during and while a stream is
affected by a storm event
primarily aquatic fauna populations, including
numbers, species diversity, and distribution
physical condition of a stream channel and its ability
to support aquatic biota
contaminants in stream and river sediment
ground water systems in connection with surface
water bodies, indlucing unconfmed aquifers,
recharge, and discharge areas for regional confined
aquifers; low in these systems does not necesarily
mimic surface topography
Typical Parameters
temperature, pH, conductivity, nutrients, bacteria, total
suspended solids, turbidity, dissolved oxygen and alkalinity
temperature, pH, conductivity, nutrients, bacteria, total
suspended solids, additional parameters can included metals,
hydrocarbons, and pesticides
macro-invertebrates and fish
wetted perimeter, bank stability, condition of substrate,
sinousity bank condition, riparian area, embeddedness and
large woody debris
particle size distribution, metals, PCBs, and pesticides
ground water levels, referred to as head
Typical Assessment
Frequency
periodic (monthly)
continuous (by event; 15-minute intervals
or flow-weighted)
infrequent (seasonal to every three years)
infrequent (every three years)
infrequent (every three years)
infrequent (seasonal to every few years)
Access to
Existing
Data
high
low to moderate
low to moderate
low to moderate
low to moderate
moderate to high
Data Type
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Table 2. Summary of Data Typically Utilized for Watershed Assessments (Cont.)
ro
ro
Data Type
Ground water
quality
Land cover
characteristics
Precipitation
Geology
Topography
Location of
permitted
discharges and
end-of-pipe water
Water intakes
Severed and
ancyroid areas
BMP performance
monitoring
Volunteer stream
monitoring
Description
water quality of the ground water systems described
above
maps, remote sensing data, and surveys of land use/
land cover
can include rainfall, rain on snow,
subsurface geologic conditions such as karst or
carbonate substrate system; depth to groundwater
contour and slope map by percent slope
conducted in support of an approved discharge permi
public wells and surface water intakes
areas served by sewer and septic
comparisons of upstream/downstream, before/
after, or inflow/outflow
conducted by trained vol unteers, civic
organizations, and school classes
Typical Parameters
pH, conductivity, nutrients, pesticides, metals, bacteria
existing and projected changes in land use and land cover
levels of imperviousness
duration, intensity, and quantity
facility-specific, depends in part on the type of facility, size of
operations, and the receiving stream
point data with drainage
land area; linked to imperviousness; potential for septic
pollution depending on density and soils
land use, channel condition (see stream structure and
physical habitat) and water quality (see storm flow water
aualitv)
physical stream condition, water quality, aquatic biota
Typical Assessment
Frequency
infrequent (seasonal to every few years)
infrequent (every five years)
continuous (by event; 15-minute
intervals or intensity-driven)
regular (bi-monthly)
infrequent
five years
infrequent (by event)
periodic (monthly)
Access to
Existing
Data
moderate to high
moderate to high
moderate to high
high
moderate
low to high
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23
Appendix A
Generic Scopefor Watershed Assessment
SECTION 1 - GOALS AND OBJECTIVES OF THE WATERSHED
ASSESSMENT
1.1 Background
1.2 Purpose Of And Need For Action
1.3 Presenting Issues
1.4 Location Of The Watershed
1.5 Scope Of The Environmental Assessment Process
1.6 Organization Of This Environmental Assessment
SECTION 2 - AFFECTED ENVIRONMENT
2.1 Location, Activities and Uses, And History Of The Watershed
2.2 Topography And Drainage
2.3 Soils
2.4 Geology
2.5 Water Resources
2.5.1 Surface Water
2.5.1.1 Hydrology And Flow Regime
By Stream Order
2.5.1.2 Surface Water Quality-
Ambient (Dry Weather)
2.5.1.3 Surface Water Quality-
Wet Weather (Storm Water)
2.5.1.4 Uses
2.5.2 Groundwater
2.5.2.1 Abundance And Depth To Groundwater
2.5.2.2 Uses
2.5.3 Floodplains
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Overview To Watershed Assessment
2.6 Climate, Precipitation, And Air Quality
2.7 Biological Resources
2.7.1 Vegetation
2.7.2 Terrestrial Wildlife
2.7.3 Aquatic Biota
2.7.4 Threatened and Endangered Species
2.7.5 Wetlands
2.7.6 Designated Resource Preservation Areas
2.7.7 Forest and Wildlife Corridor
2.8 Cultural And Historic Resources
2.9 Land Use
2.9.1 Actual Existing Land Use
2.9.2 Planned Land Use
(Zoning and Comprehensive Plan)
2.10 Transportation
2.11 Aesthetics
SECTION 3 - REGULATORY AND PERMIT REQUIREMENTS
3.1 Relevant Federal, State, And Local Statutes, Regulations, And Guidelines
3.2 Permit Requirements
SECTION 4 - IDENTIFIED NEED FOR ADDITIONAL MONITORING DATA
SECTION 5-REFERENCES
5.1 Literature Cited
5.2 Persons and Agencies Consulted
5.3 List of Preparers
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LIST OF TABLES
25
Appendix A
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 3.3
Table 4.1
Soil Series and Attributes
Surface Water Quality Data - Chemical
Surface Water Quality Data - Biological
Summary of Local Climatological Data
Summary Of Land Use Categories
Summary Of Environmental Trends
LIST OF FIGURES and MAPS
Figure 1-1 Area Location, XXX Watershed
Figure 1-2 Beaverdam Creek Reservoir
Figure 2-1 Sunrise Nuclear Power Plant
Figure 3-1 Topography And Soils In Watershed
Figure 3-2 Surface Water And Floodplain In Watershed
Figure 3-3 Wetlands And Resources Protection Areas
In Watershed
Figure 3-4 Land Use In Watershed
Figure 3-5 Recreational Uses In Watershed
APPENDICES
Appendix A Generic Environmental Assessment Scope
(Outline)
Appendix B Reports And Documents.
Appendix C Electronic Resources
Appendix D Mapping and CIS Resources
Appendix E Training Opportunities
Appendix F Important Contacts
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Overview To Watershed Assessment
Notes
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